Talk:Instrumental temperature record

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Old general discussion[edit]

I've (William M. Connolley 20:03 Feb 12, 2003 (UTC)) moved 2 paras to the end. These are:

the intro that someone copied in, viz:

"The historical temperature record shows the fluctuations of the temperature of the atmosphere and the oceans throughout history. Climate scientists generally agree that Earth has undergone several cycles of global warming and global cooling in the last 20,000 years, with the average air temparature fluctuating within a range of about 3 Celsius degrees (5 Fahrenheit degrees), over this time period."

This is mangled info. Someone can straighten it out if they like. If you look over the last 20 kyr, the biggest signal you see is the end of the last ice age - so the stuff about little cycles is then in the noise.

There are various sub-cycles/sub-signals, of ??1500 year ish?? periodicity; and their are the D-O events etc etc. But the above para mangles that. *Also* it fits rather poorly with the emphasis of this subsection-now-a-page, ie on the last 150 or 1000 years - so it shouldn't be up there in the intro.

I've also pushed

"In January 2002, scientists released data showing that Antarctica had grown about 25% (???). Some editorial writers claimed that this contradicts the expectation that rising temperatures should cause the ice cap to shrink. However, the scientists studying the situation in the Antarctic who released this data point out that local cooling in some areas is consistent with an overall trend of global warming and say that "the ice-sheet growth that we have documented in our study area has absolutely nothing to do with any recent climate trends."[9]"

into the misc section. The first sentence is junk. If its to stay, someone has to find a decent ref to what its supposed to mean. Mind you, ref [9] is nice and its a pity I've misc'd it too...


The IPCC says that it has corrected the land station data to account for the urban heat island effect. To do: find and summarize their correction technique.

The comment above has been around for about a year, and still no one has shown me where in any IPCC report they have explained how they "account for" urban heat islands. So I'm inclined to say rather:

Critics of the IPCC report note that it fails to explain how it accounts for the urban heat islands. These critics argue that the heat island effect correlates with land-based thermometer readings better than the global warming theory espoused by the IPCC.

... or something along those lines. Work with me here, folks. Let's make an informative and neutral article. --Uncle Ed

That looks fairly reasonable - I'd modify slightly:

The IPCC report does not explain how it accounts for the urban heat island effect - increased warming due to proximity to major cities. The heat island effect, if not properly accounted for, would tend to increase the amount of apparant warming.

Martin

(William M. Connolley 09:46 Feb 13, 2003 (UTC)) There is at least a problem in the wording here. IPCC doesn't do research, it reports other peoples. But apart from that... see section 2.2.2.1 [1]. In particular:

These results confirm the conclusions of Jones et al. (1990) and Easterling et al. (1997) that urban effects on 20th century globally and hemispherically averaged land air temperature time-series do not exceed about 0.05°C over the period 1900 to 1990 (assumed here to represent one standard error in the assessed non-urban trends). However, greater urbanisation influences in future cannot be discounted. Note that changes in borehole temperatures (Section 2.3.2), the recession of the glaciers (Section 2.2.5.4), and changes in marine temperature (Section 2.2.2.2), which are not subject to urbanisation, agree well with the instrumental estimates of surface warming over the last century. Reviews of the homogeneity and construction of current surface air temperature databases appear in Peterson et al. (1998b) and Jones et al. (1999a). The latter shows that global temperature anomalies can be converted into absolute temperature values with only a small extra uncertainty.

Errr... shouldn't all this go into the UHI page?

Yep. And then summarised here. :) It all seems rather a lot of work... :-/ Martin
William, the large quote above (0.05°C over the period 1900 to 1990) seems at first reading to answer Martin's other question: are heat islands causing global warming. My question is different: are temperature readings taken within heat islands giving a false impression of global warming. That is, (1) if a city gets 0.8°C warmer, and this warming is averaged in with all other temperature differences, I think this would be a statistical error. What do you think? Also, (2) if cities get much warmer, suburbs get kind of warmer, rural areas get a bit warmer, and uninhabited areas don't get warmer at all, what would this tell us? (Not saying that's the case for now, just asking what this would tell us if it were so.) --Uncle Ed 17:19 Feb 13, 2003 (UTC)
AFAICT, "globally and hemispherically averaged land air temperature time-series" - I think this phrase is referring to the temperature readings rather than the actual temperatures - IE, it answers your question... Oh, I'm copying some of this stuff to the urban heat island page. Martin
There is an answer to UE from IPCC. Essentially, you can (if you wish) separate out the obviously-likely-to-be-affected stations if you like, but it makes little difference. Reasons include: cities are small areas anyway; the trends from cities (etc) don't in fact differ substantially from the trends without them; in fact the trends over city areas agree quite well with the dreaded MSU... I'll try to find this and add it in, since its clearly a concern (William M. Connolley 21:31 Feb 13, 2003 (UTC)).

I have started studying a paper on the temperature record in the USSR. The writers find no warming trend in rural stations and hint (or imply) that other researchers have selectively chosen data to fit their "warming" views. [Read it yourself] and decide. --Uncle Ed 17:52 Feb 13, 2003 (UTC)

Its worth reading (William M. Connolley 21:36 Feb 13, 2003 (UTC)). I've had a brief look before. Of the 2 stations I picked to check his analysis, one had the jump he claimed (according to objective statistics) and one didn't, or it was impossible to tell: the trends he claimed as implausible against "neighbouring" stations were from places 100's of km away, and in different exposures: near the sea or not.

Martin and William,

I'm not sure either of you is getting my point. I am not wondering whether a few hot cities are making the whole world hot.

I am wondering whether a large number of the temperature readings from weather stations in and near rapidly warming cities, when averaged with a relatively small number of temperature readings from rural and remote stations, are giving a false impression of global warming. That is, it might be that (A) the only parts of the world that are warming are the urban heat islands and (B) the only reason these are heating up is because cities absorb and generate heat; rather than (C) that carbon dioxide, etc. is causing worldwide warming.

Do you understand my point? (I'm not asking whether you agree with my point of view, but only whether my English is clear.) --Uncle Ed 22:33 Feb 13, 2003 (UTC)

I believe so - let me paraphrase to try and prove it.
* Because of the urban heat island effect, cities are warming up more than the surrounding countryside
* Thermometers are recording an increase in temperature
* Many thermometers are located near urban heat islands
* Therefore, the temperature increase recorded by thermometers may overestimate the actual temperature increase of the climate as a whole.
To draw a parallel, one shouldn't put the thermostat in one's house next to a log fire, because in that case the thermostat will overestimate the general temperature of one's house.
My reading of the IPCC report is that the distortion introduced by the urban heat island effect is, at most, 0.05°. In other words, if we had located our thermometers away from urban heat islands, they would have recorded 0.05° less temperature increase over the period 1900 to 1990. Of course, this depends on whether you trust the research cited by the IPCC... Martin
I mostly agree with Martin. Have you read the bit about marine and borehole temperatures? This does a lot to counter your point. I also think you're wrong to suppose that, numerically, urban reading predominate. Martin: note that strictly speaking IPCC reprots that UHI leads to at most 0.05 *uncertainty*. They don't (I think) explicitly state that this is necessarily in the warming direction.

Thank you, both, for helping me to feel understood. Now I'll have a G-R-E-A-T weekend! ^_^ (Uncle Ed)

Subsurface ocean temps[edit]

This article erroneously defines the ITR as being only about surface temp. That's false, but I don't enough about the subsurface instrumental record to write good text. Help please? — Preceding unsigned comment added by NewsAndEventsGuy (talkcontribs)

Um. Initially the instrumental temperature record only documented land and sea surface temperature, but in recent decades instruments have also begun recording sub-surface ocean temperature is too simplistic. People have been documenting sub-sfc temperatures for ages. The correct sequence is land-sfc before the others, then ocean sfc thinly, with sub-sfc coming in slowly. The difference in recent decades is in volume of coverage, ie quantitative, not qualitative William M. Connolley (talk) 12:54, 28 January 2014 (UTC)
I'd welcome your expertise revising the text to include subsurface! You say "ages", and I don't know...I'm a layman. But I can read, and in Mann & Krump's "Dire Predictions", in the glossary, it says the land surf record is 150 years, and ocean subsurface record goes back only 5-6 decades. If that's "ages" for subsurface then I guess I agree. How would you phrase it better? And please do! NewsAndEventsGuy (talk) 13:09, 28 January 2014 (UTC)

Is there any reason why the warmest decades aren't written in their most familiar form?[edit]

Also, they are in the reverse order. Sagittarian Milky Way (talk) 23:47, 21 January 2015 (UTC)

You can reverse order by clicking at the top right-hand side. I'm trying to update using the data source which has been updated since 2009 but 1st checking math on the table as stated in the article. http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt I may have some questions :)2601:C:6783:8416:BD19:9DFE:2A64:FBE3 (talk) 19:40, 16 February 2015 (UTC)

User Afasmit added false data[edit]

This edit from August 2014 https://en.wikipedia.org/w/index.php?title=Instrumental_temperature_record&diff=prev&oldid=619368050 added various errors to annual data, based on a cite which points to monthly averages. prokaryotes (talk) 12:22, 10 May 2015 (UTC)

All I did was add data for 2013 and appropriately round the numbers already there, following the referenced sites previous editors had entered. The water-and-land-combined numbers look virtually the same as they are after your edits anyway (I suppose somehow separate land and water annual deviations are not available). Also, us eukaryotes don't go around yelling from the rooftops that someone made a mistake. Afasmit (talk) 01:56, 11 May 2015 (UTC)
I'm sorry but mistakes need to be pointed out in this matter, and we need to use official numbers here, and this is also relevant for other editors. We are all a little guilty, sorry if i made a to strong remark, thanks for your reply. prokaryotes (talk) 02:09, 11 May 2015 (UTC)

Articles for individual years[edit]

Anyone else interested to add new articles for individual years? prokaryotes (talk) 12:44, 10 May 2015 (UTC)

I'm somewhat dubious; you'd need RS's for saying stuff. Are there really many years to say interesting things about? William M. Connolley (talk) 17:10, 19 May 2015 (UTC)
We could start with exceptional years, such as 1998 (El Nino), 2007(record low sea ice extent), 2014 (hottest year), 2020 (Disintegration of ice sheet X) etc. I think establishing dedicated articles can help to understand the context of climate change better, and it would help to track remarkable events from the past. A list article could then offer an overview of the exceptional years. prokaryotes (talk) 17:46, 19 May 2015 (UTC)
This article isn't very long. For what it's worth, my suggestion would be to write the text you propose for these years as subsections here - maybe under an overarching section heading like Exceptional years. If they work out and they're getting long, they can be split out into separate article(s) per WP:SPLITOUT. --Nigelj (talk) 18:15, 19 May 2015 (UTC)
Hmm, but this article is dedicated to the temperature records, adding a sub section with content about El Nino, or sea ice seems a bit to broad. Rather, once there are dedicated articles, sub sections here with the scope on temps, could then direct to the main article. prokaryotes (talk) 19:14, 19 May 2015 (UTC)
I'm also dubious, but that's only because the proposal is entirely vague and I'm not feeling creative at the moment. If you develop a draft in your userspace, then the rest of us would have an example, and then we could give a more substantive response. NewsAndEventsGuy (talk) 00:38, 20 May 2015 (UTC)
Okay, will prepare something with a ruff outline, maybe in the next 24 hours, maybe a bit later (: prokaryotes (talk) 01:12, 20 May 2015 (UTC)
We already have articles on significant individual weather events, e.g. Blizzard of 1977, 2006 European heat wave. I suppose a page like Weather of 2014 could provide a unifying home to discuss the events of the year. One should keep in mind though that on the time scale of a single year, most of the interesting bits are actually extreme weather processes, whereas climate (and climate change) is generally less of an issue. Dragons flight (talk) 05:44, 20 May 2015 (UTC)
Just noticed these articles for events and individual years https://en.wikipedia.org/wiki/2014 prokaryotes (talk) 17:19, 21 May 2015 (UTC)